The present invention is an apparatus for closing the type of box that has a cover hinged to the body portion and is locked in closed position when the cover is swung over onto the body portion and flanges that extend out from the front edges of the cover and body portion, respectively, are pressed together so that one or more projections or buttons on one of the flanges is forced into mating well or wells in the other flange and snaps into locked relation therein. This type of locking means is sometimes referred to as a press-button snap lock closure.
These types of boxes on the the press-button snap lock type of closures are used are customarily made of thin plastic so that their walls are naturally relilient and flexible. The locking of th box cover in closed position is provided by pressing the one or more projections or buttons on one flange into the mating well or wells in the opposing flange. The projections or buttons are undercut at their bases so that they are larger at their outward ends than at their bases. The openings of the mating wells are made slightly narrower than the outer ends of the projections but the other portions of the wells are large enough to accommodate the mating projections. Thus, due to the natural flexibility and resilience of the thin plastic walls of the box, the projections or buttons snap into and are retained in the mating wells when the box cover is swung over onto the box body portion until the flanges are together with the projections or buttons studs alligned with the mating wells and the flanges pressed together to push the projections or buttons into the wells.
Boxes of this type are currently used for packaging bakery products such as muffins. The boxes are preferably made of a clear plastic that is rigid but flexible when it is formed into thin walled boxes. Thus the goods in the boxes are clearly visible for sales appeal, are rigid enoungh to protect the contents and are thin walled enough to keep the cost down and to make possible the simple and effective projection and well locking system just described above.
The box closing apparatus of this invention is particularly adapted for closing and locking boxes of the foregoing type. Heretofore boxes of this type as used on production lines in commercial bakeries for example have been filled and closed by hand. That is, open boxes moving along on a conveyor belt are filled with muffins or other products by hand at one work station and then closed and locked in closed condition by hand at another work station. Pressing the flanges of these boxes together to snap the projections or buttons into the mating wells is particularly fatiguing and irksome for the workers and is the type of hand work motion that is likely to cause carpal tunnel syndrome.
Up to this time there has not been available any suitable or effective machine or apparatus to automate the tedious and potentially damaging work of closing and locking these boxes so that it has had to be done by hand up until now.